Watching water freeze in the name of science

TRURO — Dick and Carol Spokes carefully made their way down an icy path to Snow Pond on Friday morning with an excitement that only other "ice monitors" might understand.

The air temperature was 34 degrees — not quite freezing, but good enough.

"Last year, we went every week with our little data sheets, waiting to see some ice, and I think one day, it must have been the end of February, we actually saw ice," Dick Spokes said.

The Spokes, both of whom are 70, are originally from Vermont but retired in Eastham, and they're among a handful of volunteers who monitor the formation of ice on three ponds in the Cape Cod National Seashore: Snow Pond in Truro, and Great Pond and Long Pond in Wellfleet.

The study of ice formation is common in northern states, the Great Lakes regions and the Midwest, according Seashore aquatic ecologist Sophia Fox.

For the Seashore, data about the timing of ice formation will also contribute to an existing study of 20 ponds, dating from the 1970s, which looks in part at annual patterns of cold and warm water mixing in ponds and how that affects water quality, Fox said.

The monitoring is also part of a larger, decades-long study that began in 2012 of the life cycle — or phenology — of many Seashore organisms and physical features, such as freshwater wetlands and adjacent woodlands, maritime dune shrub communities, salt marsh vegetation and red-winged blackbirds.

This study will record when natural processes — such as ice forming, flowers blooming or birds migrating — occur, to establish baselines and to understand what trends exist and how those trends might be influenced by larger forces such as climate change.

Much of the phenological data will be added into a national database, as well.

"I have to tell you, though, I don't think we're going to be doing this for 30 years," Dick Spokes, a retired environmental land use lawyer, joked as he drove toward Great Pond.

"We're hoping to make 10," Carol Spokes, a retired nurse, said from the back seat.

This year on the pond off Route 6, snow covered nearly the entire surface of the water. The ice around the edge withstood stamping shoes.

A branch skidded across without sinking. Granted, a few black patches of water were cozy against the far shore. But, no doubt, this was a home run.

"We'll be in what they call Category 4," Spokes said, referring to the highest percentile of ice coverage on the data collection sheet provided by the Seashore.

The monitoring occurs weekly from December through April on Mondays, Wednesdays, Thursdays and Fridays.

Volunteers rate the ice formation from a "0," where no ice is visible on the surface, to "4," where 76 percent to 100 percent of the surface is covered with ice.

In 2012, the volunteers recorded 79 observations, with ice reported in 16 of those, or about 20 percent, according to Seashore monitoring and research coordinator Megan Tyrrell.

In those 16, the majority had less than 50 percent ice coverage.

"At no point does it appear that any of the ponds ever completely froze over," Tyrrell said Thursday, about last year.

But, she added, one year's worth of data is not enough to make a connection between ice formation on the ponds and the warming climate.

"The fact of the matter is, that the study of climate requires long-term data sets from which we can determine averages, and that's the intent of the phenology monitoring program," Tyrrell said.

For the Spokes, who belong to the nonprofit Friends of the Cape Cod National Seashore and who helped recruit volunteer ice-watchers, the monitoring is fun.

"The interesting result is that when you walk in the woods, you begin to notice these phases," Dick Spokes said. "You really do. You're going to watch when the first robin appears and when leaves form."

Fact Box

ICE MONITORING

The Cape Cod National Seashore has begun its second year of monitoring ice on three ponds in Wellfleet and Truro, part of a planned, decades-long effort to record the life cycles of organisms and physical features, and ultimately to reveal trends that reflect how the climate and other forces are shaping the timing of these natural events.